Field of the Disclosure
The present invention relates in general to building products and, in particular, to an improved system, method and apparatus for variegated building products.
Description of the Related Art
Building products such as vinyl siding panels and roofing tiles are widely used for protecting the exterior walls and roofs of buildings, respectively, as well as for enhancing the exterior appearance of buildings. These building products may have different profiles and exterior finishes to provide variety in the exterior appearance of a building. Typically, the siding panels and roofing tiles are nailed or otherwise secured to the building to fix them in place.
Formerly, in constructing vinyl siding panels, it was customary to extrude a sheet of vinyl with the entire profile formed therein, and to then cut the sheet of vinyl into panels of appropriate lengths. The sheet utilized conventional color concentrators designed to give it a desired coloration properties. The sheets could also be embossed or otherwise formed to add ornamentation to more closely simulate natural wood building products.
Some siding is post-formed vinyl siding, in which the siding is extruded as a flat sheet and then formed into the desired shape in post forming operations. Rather than forming solid vinyl siding panels, other siding products are co-extruded panels having a base substrate and an outer layer. The outer layer is commonly called a capstock. The substrate layer is hidden from view when the siding is applied to a building, and is typically formed of conventional, relatively inexpensive but sturdy polyvinyl chloride (PVC). The substrate typically utilizes conventional color concentrators designed to give it a desired coloration properties. The outer layer forms the exposed or outer component of the vinyl product.
Existing products are limited to extruded siding or plank products. There is a need for variegated products that are produced by injection molding. Current methods for producing multi-color woodgrain appearance include applied films and coatings. However these products are challenged by long term durability performance issues such as color-hold, adhesion and abrasion.
Other options include extruded capstock that may be formed of the same composition as the substrate and may include a color material that forms accent color streaks. These methods can produce variegated siding panels having a natural, wood grain-like appearance. It would be desirable to produce a variegated building product using injection molding equipment.